Bake oven conveyer



Dec.

4, 1945. J. R. NALBACH BAKE OVEN CONVEYER `Filed oct. 26. 1944 2sheets-sheet 2' bakeoven conveyers.

'veyen partially` in section, taken Patented Dec. 4, 1945 UNITED STATESPATENT I 01E FI CE. i

BAKE OVEN coNvEYan` 301m n.` Nalbach, `oak Park, n1.,--assignor`to `iMiddleby-Marshall Oven Company, Chicago,"

VIlll, a corporation of Illinois v Application october 26,1944, serialiva-560,467

This invention .relates` to; :improvements in VIn` the conveyerconstructionv for bake ovens, shown in John R.; Nalbach and `AdolphHaupt application, SerialoNo. 435,774,4led March 23,

1942, now PatenttNo.: 2,369,840, `grantedFebruary 20,v 1945, thereisshown j tray stabilizing mechanism,gincluding track switches, fordirecting un- `pivoted` ends of trays across gaps orfspaces betweenhorizontal lower maintracks and superjacent arcuatertracks, alongthelatter `of which said unpivoted; ends of :thetrays travel inmovn ingfrom" one run-o theconveyer to the'other, the track switches beingcamicontrolled.

n `.The-principal` object of, the present invention isytoirnprove thetrack switch and related structure shown in said patent by incorporatingtherein means `for preventing jamming of the moving 4conveyer or trayparts `with :the: track switches in the event the latter `fail to moveout of obstructing position, due to failure or improper functioning ofthecam controlled means thereof.

Another object of the invention is to provide a. simple track switchstructure thatis operable to `anpopen switch position by thoseapproaching portions of the tray conveyer` mechanismfthat will causejamming of the mechanism in the event the switch structure, due tointerference withthe proper functioning ofthe switch oper.-

` ating means, fails to return normally to the open `switch position. Y`Other objects of the vinvention relate to various features of`construction and arrangement i view: of "the right-hand portion of theconveyer shown in Figure 1;

AFigure 3 is a broken `perspective view illustratlng `portions of thetrack switch and related mechanism;`

`Figure 4 is a` broken top plan view of the conalong lines 4 4 of`Figure 1.

Inthe drawings, .I indicatesgenerally a heatinsulated bakev ovenenclosure whichmay be of `any approved construction and within which islocated the improved conveyer.` .Therconveyer mechanism, generally,.comprises a` pair of forward sprockets I I, spaced .aparthorizontallmand a pair of aligned rear sprockets I 2 around whichl pass a pair ofchains I3. The runs of the chains between thefront andlrearsprockets IIandil2 are shown inhorizontal position `and are sup-V ported in suchposition `loylrneans of a paircf upper tracks I4 and a similar pairoflower tracks I5, the tracks being attached to the inner Walls of theoven structure or to the framework thereof.` As shown in Figure 1, theconveyer mechanism may be operated by means of a mo tor I6 locatedexteriorly of the ovenythe` motor operating chains VI 'I which, in turn,drive sprockets I8 mounted on axially alignedstub shafts I9 which carrythe frontsprockets II. The shafts I9 extend through opposite walls ofthe oven to the exterior, whereby the driving means for the conveyer arenot subjected to` the `intense heat of the oven.

The chains I3 carry trays,` each indicated by the numeral 2D, althoughtosome of the latter letter exponentswill befadded for clarity inreferencerto particular trays as the disclosure proceeds. i

The trays carry the bread or other bakery productsto be baked, and inthe particular embodiment herein illustrated the trays are attachedpivotally to opposed portions of the chains I3 by lateral extensionsorpivot members 2|, as indicatedin Figure 4. In Figure 4 it will benoted that the tracks I4 and I5 extend inwardly of the oven beyond thechains I3 and thusprovide inner trackways along the inner edges of the`tracks which are indicated by numerals Ha and 15a.` The pivot members2I extend across the trackways just. mentioned into pivotal en'-gagement with the chains and, hence, are moved with the chains as thelatter travel under the `driving action of themotor I6. The forward endsof the trays 20, as shown in Figure 4, are `provided with supportingmeans therefor in the form of rollers 22 whichare arranged for` supporton the trackways Maand I5a on the upper and lower tracks I4 and I5.l Itwill be seen, therefore, that the trays 2B are supported in horizontalrelation as the same move longitudinally in one direction or` otherwithin thefoven.

Referring to Figure 1, it will be seen that if the conveyer mechanism isoperating in clockwise direction, the pivotal axis 2I of the respectivetrays in the upper run ofthe conveyer will be moved arcuately by thechains about the rear sprockets. I2 andthus will be carried fromtheupper rtracks to the lower tracks. For the purpose of supporting theforward ends of such V -trays duringthe arcuate movements thereof fromone run of the conveyer to the other,1 mechanism is provided forengaging the forward unpivoted ends of the trays and retaining the samein horizontal alignment with the rear pivoted ends thereof during sucharcuate movement. The mechanism herein shown and also disclosed in theabove mentioned patent comprises a pair of rotary transfer members 24each of which is mounted on one oftwo similar stub shafts (see Figure 4)that are driven in synchronism with the sprockets I2 by any suitablemechanism, such as chains 26, sprockets 21, and sprock-V ets 28, thelatter being mounted on the stub shafts I2a that carry sprockets I2,said driving mechanism being located exteriorly and on o-pposite'sidesof the baking chamber.

The transfer arms 24, as shown in Figure 4, are located substantially invertical alignment with the respective inner edge portions of the tracksI4 and I5 and, by reason of the drive mechanism above described, themovements thereof are synchronized with the movements of the successivetrays so that as the rear end of a tray, such as tray 20a, shown inFigure 2, approaches the rear sprockets I2, one end of eachtransfer arm24 will be in position, as shown in said figure, to engage rollersmounted co-axially with respect to the adjacent rollers 22. `As the rearpivotedl end 2| of the tray 20a begins its downward arcuate movementabout the sprockets I2, the forward unpivoted end lof the tray,supported by the transfer arms 24 will begin to move arcuately downwardalso, whereby the tray is retainedV during such arcuate movements inhorizontal or stabilized relation.

In Figure 1 a tray indicated by the numeral 2Gb is shown in a positionmidway between the upper andV lower runs of the conveyer. The rearportion of the tracks I4, as described in the above mentioned patent,are cut away sufficiently as at 3| (see Figure 2) to accommodate thearcuate movement of the forward ends of the tray under the guidance ofthe transfer arms 24. For the purpose of cooperating with the transferarms in the stabilization of the respective trays during the arcuatemovement of the latter, arcuate track members 32 are disposed in thevertical planes of the respective transfer arms 24. The arcuate trackmembers cooperate with the receiving recesses 24a of the arms 24 inguiding the rollers 3|) during the arcuate movement mentioned. Since therear pivoted ends of the trays extend laterally beyond the verticalplanes of the arcuate track members 32, the lower ends of the latterterminate above the lower tracks I5, thereby providing a gap or spacebetween said members.

Such gap or space is required to permit the rear pivots 2| of the traysto pass horizontally along the lower track beneath said arcuate tracks32 after a tray, such as tray 20e of Figure 1, has reached the lowertrack I5.

For the purpose of cooperating with the transfer members 24 in guidingthe unpivoted ends of the trays across said gaps at the lower ends ofthe arcuate tracks 32, track switches 33 are provided which are disposedin the vertical planes of 'the respective arcuate tracks. The trackswitches 33, as shown more clearly in Figure 3, are mounted on stubshafts 34 each of which, on an outer end is provided with a cam followerarm 35 having a cam follower 36' thereon, the latter being actuated bya, cam 3l mounted on the respective shafts 25. The cams 3l, during theoperation thereof, rock the arms 35 and the shafts 34 forthe purpose ofmoving the track SWiChQ 3'3 to the switching position shown in Figures 2and 3. The non-switching position of a switch is shown in Figure 1.While the track switches 33 are in the positions indicated in Figure 1,the pivot extensions 2| at the rear of the respective trays can passalong the lower tracks I5 beneath the lower ends of the arcuate tracks32. When the track switches 33 are in the position shown in Figures 2and 3 they formarcuate eX- tensions of the tracks 32 and thus cooperatewith the latter and with the transfer arms in guiding the forwardunpivoted ends of the respective trays from the tracks 32 onto the lowertracks I5, as

suggested by tray 20c in Figure 2.' Thecams 31 l are arranged toVoperate the track switches 33 in synchronism with the arcuate movementsof the vtrays from one horizontal run of the conveyer to the otherregardless of the direction of movement of the conveyer. f

For the purpose of causing the follower` arms 35 to tend to swing to theright or clockwisey as viewed in Figure2, and thereby retain the cam- 1in properly timed relation with respect to the movement of thepivotedends of-a tray beneath the arcuate tracks 32, theswitches wouldVobstruct 1 the horizontal movement of the pivoted ends of the tray andcause damage to the apparatus. "To

avoid such damage the track switches shown in Y the present applicationare designed to prevent such damage from the cause mentioned and, aswill be seen in the drawings, the rearportion'sl of the track switches33 are provided with inclined cam surfaces 4| which, in the event thetrack switches fail to vmove out of the bridging relation between thelower tracks l5 and the lower ends of the arcuate tracks 32, will beengaged by the f pivotal extensions 2| of an approaching tray', therebyforcing the-track switches 33 downwardly in a clockwise direction.Forthe purpose of preventing the cam surfaces 4| of the track switchesfrom effecting elevation of the chains VI3 as the pivotal extensions 2|engage said surfacesV 4|, guard rails 42 are provided, as shown inFigures 2 and 3, which prevent such upward deection of the pivots 2| andthe associated links of the chains. The guard rails 42 extend inwardlyover the adjacent `portions of the lower runs of the chains |3 and areshown mounted on the sliding structures A in which the shafts I2, 25 and34 are journalled and which structures are biased by springs B formovement to the right for tensioning the chains I3 while accommodatingexpansion and contraction and wear thereof, as disclosed in the abovementioned patent.

It will be seen that by means of the present of the conveyer mechanism.Y In the event the conveyer is being operated accesso son 'of the shafts34 'thereof-freezing in their bear- Y ifi-gs, `the switches would tendto elevate the pivdtvd end-of stray as the pfvdt' memberstherecf'rijgagethe usersurfsces ort-ne switehesfa'a Fdfthe purpose ofVcausing the pivot members '21 tfiiferce tneswitches `out offeneneie'vated or bridging" positions under 'such conditions,` guard rails4,4, arepositioned above the lower `run `of the' Achains |13 and to theleft of the arcuate tracks 32 as viewed in Figure 2. These rails 44 maybe secured to the respective oven walls and prevent upward deflection ofthe chains from theA lower tracks l5, and hence, should the switchesremain in the elevated position as the pivots 2l approach them in movingto the right, the switches will be cammed out of the elevated positionby said pivot members and the pivoted ends of the tray will thus notengage the lower` ends of the arcuate tracks 32 but will passthrough'the switch spaces beneath the arcuate tracks 32. v

It will therefore be seen that a safety switch mechanism has beenprovided whereby, in event `oi. failure of the switchesto move in propersequence out of obstructing position to permit horizontal passage alongthe lower tracks of` the laterally extending pivot members 2l of thetrays, `said members 2l, in approaching said switches, will cam them outof such obstructing positions.

At the forward end of the conveyer the structure is `similar to thatdescribed in the above `mentioned patent and comprises transfer arms 45,

each mountedon suitable shafts 46, driven from shafts I9 by means ofchains 41 passing over sprockets 48 and 49. Arcuate track members 50constitute in eifect forward extensions of the lower tracks l5. As atray, such as tray d in Figure 1, in moving to the left approaches theposition where the rear pivotal extension 2l thereof begins to movearcuately about the sprockets Il, the transfer arms 45 will have engagedthe rollers 22 at the forward ends of the tray and incooperation withthe arcuate tracks 50 will retain the tray in horizontal relation duringthe subsequent arcuate movement, as indicated by tray 20e, in Figure l.During the transfer arcuately from one horizontal run of the conveyer tothe other the mechanism described operates simi-` larly pegardless ofthe direction of rotation of the conveyer, that is, whether the trays inthe upper run of the conveyer move to the right or to the left as viewedin Figure l. Successive trays, in moving to the transfer position ateither spaces to provide extensions of said arcuate tracks for guidingtray portions across said spaces, means for moving said switches tonon-switching position, and means on said switches cooperable with otherportions or tnetfays 'for moving issie switches out of switchingposition upon failure of said means to move said switchestonen-switching position as said other tray portions approach said'spaces.

2. In a tray conveyer mechanism provided with upper and lower tracks,arcuate tracks disposed Vbetween said upper and lower tracks and spacedfrom the latter, track switches providing extensions cf 'said arcuatetracks; Vfor bridging the spaces-between said arcuate tracks andlowertrackslfordirecting tray portions across said spaces," means `formoving" said switches to` said bridging positions, and means engageableby other portions of the trays for moving said switches out of saidbridging positions.

3. In a tray conveyer mechanism provided with upper and lower tracks,arcuate tracks disposed between said upper and lower tracks and spacedfrom the latter, track switches providing extensions of said arcuatetracks for bridging the spaces between said arcuate tracks and lowertracks for directing tray portions across said spaces, means for movingsaid switches to said bridging positions, and cam means carried by saidswitches and disposed by the latter in the path of other portions of thetrays when the switches are in bridging position for engagement by saidother tray portions for moving the switches out of bridging position assaid tray portions approach said spaces.

4. 4In a tray conveyer mechanism comprising `tracks being spaced fromsaid lower tracks to provide passages through which the pivot members ofsuccessive trays are arranged to pass in moving along said lowerhorizontal run, track switch members movable into saidspaces to bridgesaid spaces for cooperation with said rotary members in moving saidunpivoted portions of the trays across said spaces, cam means for movingsaid switches intermittently into said bridging positions in timedrelation with respect to the arcuate movements of the successive trays,and means adapted to be operated by said pivot members of said trays tomoving the switch members out of said bridging positions as therespective pivot members approach said spaces.

5. In a tray conveyer mechanism comprising endless chains, traysprovided with laterally extending pivotal members secured to saidchains, upper and lower tracks for supporting said chains, arcuatetracks disposed between said upper and lower tracks and spaced from thelatter, track switches providing extensions of said arcuate tracks forbridging the spaces between said arcuate tracks and lower tracks fordirecting tray portions across said spaces, cam means for moving saidswitches to said bridging positions, biasing means for moving saidswitches out of said bridging positions alternately with respect to themovements thereof by said cam means, and means on said switch` lmembersengageable by the pivotal members of a tray approaching said spaces formoving said switches out of switching positions inthe event saidswitches'are not so moved by said biasing means. Y

V6. In a, tray conveyer mechanism comprising endless chains, traysprovided with laterally extending pivotal members secured to saidchains, upper and lower tracks for supporting said chains, arcuatetracks disposed between said upper and lower tracks and spaced from thelatter, track switches providing extensions of said arcuate rtracks for4bridging the spaces between said arcuswitches to said bridgingpositions, biasing means portions. H

*,for moving saidv switches out of said bridging positions alternatelywith respect to the movements l ,thereof by said cam means, cam portionson said switch members engageable by the pivotal members of a trayapproachingsaid spaces for moving said switches out of switchingpositions in the event said switches are not so moved'by said bias'- ingmeans, and means for constraining said pivot.- a1 members againstdeection Afrom` the normal paths of movementby engagement with said camJOHN RNALBACHI

